GENERAL REMARKS ON STAINING 
71 
gymnosperm microspores are cyanophilous like the male generative 
nuclei. The nuclei of a nucellus surrounding an embryo sac are also 
cyanophilous, while the nuclei of structures within the sac are erythro- 
philous. His conclusion is that the cyanophilous condition in both 
cases is due to poor nutrition, while the erythrophilous condition is 
due to abundant nutrition. A further fact in support of the theory 
is that the nuclei of the adventitious embryos which come from the 
nucellus of Funkia ovata are decidedly erythrophilous, while the 
nuclei of the nucellus to which they owe their food-supply are 
cyanophilous. 
In division stages nuclei are cyanophilous, but from anaphase 
to resting stage the cyanophilous condition becomes less and less 
pronounced, and may even gradually change to the erythrophilous. 
An additional fact in favor of this theory is that in Ephedra the 
tube nucleus, which has very little cytoplasm about it, is cyanophilous. 
Strasburger claimed that there is no essential difference between 
male and female generative nuclei, and subsequent observation soon 
showed that within the oospore the sex nuclei rapidly become alike 
in their reaction to stains. 
Malfatti (1891) and Lilienfeld (1892-1893) claim that these 
reactions are dependent upon the amount of nucleic acid present in the 
structures. During mitosis the chromosomes consist of nearly 
pure nucleic acid and are intensely cyanophilous, but the proto¬ 
plasm, which has little or no nucleic acid, is erythrophilous. There is 
a gradual transition from the cyanophilous condition to the erythro¬ 
philous, and vice versa, the acid structures taking basic stains and 
basic structures the acid stains. 
The terms “erythrophilous” and “cyanophilous” soon became 
obsolete, and many claimed the affinity is for basic and acid dyes, 
rather than for blue or red colors. That the terms were misnomers 
became evident when a combination like safranin (basic) and acid 
green (acid) was used, for the cyanophilous structures stained red, 
and the erythrophilous green. 
According to Fischer (1897 and 1900), stains indicate physical 
but not chemical composition. Fischer experimented with sub¬ 
stances of known chemical composition. Egg albumin was shaken 
until small granules were secured. These were fixed with the usual 
fixing agents, and then stained with Delafield’s haematoxylin. The 
extremely small granules stained red, while the larger ones became 
